Risk assessment and seroprevalence of bovine herpesvirus type 1 infection in dairy herds in the inner Aegean Region of Turkey

Abstract

This cross-sectional study was performed to investigate the seroprevalence and associated risk factors of bovine herpesvirus type 1 (BoHV-1) infection in dairy cattle herds in Afyonkarahisar province in the Aegean Region of Turkey. Blood samples were collected from 602 cattle from 56 unvaccinated dairy herds between May 2018 and June 2019. Animal and herd-level epidemiological information was collected with a questionnaire during blood collection. Specific antibodies against BoHV-1 and bovine viral diarrhea virus (BVDV) were detected by using a virus neutralization test and a commercial indirect ELISA kit, respectively. Univariable and multivariable logistic regression analyses were used to determine any association between categorical variables and BoHV-1 seropositivity. The animal-level and herd-level seroprevalences of BoHV-1 infection were determined to be 39.53% (95% confidence interval, CI: 35.71–43.50) and 73.21% (95% CI: 60.41–83.04), respectively. Within-herd prevalence was more than 50% in 34.14% of infected herds. Cattle age (odds ratio, OR= 2.34, 95% CI: 1.58–3.44), BVDV infection (OR= 7.74, 95% CI: 5.08–11.76), and the presence of goats in the herd (OR= 2.84, 95% CI: 1.91–4.19) were identified as risk factors for BoHV-1 seropositivity by the multivariable logistic regression model. This is the first study conducted in Turkey using two-layer sampling and logistic regression analyses to determine the herd-level and animal-level seroprevalence and associated risk factors of BoHV-1 infection.